4 Supplements Everyone Over 40 Should Know

Creatine, calcium, vitamin D, and magnesium are often marketed to adults who want stronger muscles, healthier bones, better balance, and easier recovery. Each nutrient has a legitimate role in the body, but supplements do not replace strength training, balance work, walking, nutritious food, sleep, or medical care.

After 40, changes in recovery, strength, balance, or joint comfort may become more noticeable.

Your knees may complain after stairs. Your back may need more preparation before yard work. Your balance may feel different stepping off a curb. A workout, hike, golf round, tennis match, or long walk may require more recovery than it once did.

That does not mean decline is unavoidable.

Strength, mobility, balance, endurance, sleep, nutrition, medical conditions, medications, and activity habits all influence how your body performs.

Supplements may support some of these areas, but they are not the main engine.

Start with the foundation

Before considering a supplement, look at the parts of health that usually matter more:

• Progressive resistance training
• Regular walking or aerobic activity
• Balance and coordination exercises
• Adequate protein and total food intake
• Calcium- and magnesium-rich foods
• Appropriate vitamin D intake
• Consistent sleep and recovery
• Management of medical conditions
• A rehabilitation plan when pain or movement is limited

For adults at increased risk of falling, exercise has more consistent evidence than vitamin supplementation alone.

A 2024 evidence review for the U.S. Preventive Services Task Force found that exercise interventions reduced falls and injurious falls among community-dwelling older adults at increased risk. These programs often included balance, strength, gait, and functional training (Guirguis-Blake et al., 2024).

Supplements should therefore be treated as possible support—not as the primary fall-prevention or mobility strategy.

Four supplements adults often ask about

The supplements most frequently connected to muscle, bone, and physical performance include:

• Creatine
• Calcium
• Vitamin D
• Magnesium

Each has a different purpose.

Each also has limitations, possible side effects, and situations where supplementation may be unnecessary or inappropriate.

Creatine: Possible support for resistance training

Creatine helps the body rapidly regenerate energy used during brief, demanding muscular efforts.

That makes it relevant to activities such as:

• Strength training
• Rising from a chair
• Climbing stairs
• Lifting groceries
• Short bursts of higher-intensity activity
• Rebuilding strength after a period of inactivity

Creatine is often associated with bodybuilding, but research has also examined its use in middle-aged and older adults.

A 2021 meta-analysis found that creatine supplementation combined with resistance training produced greater gains in lean tissue and strength than resistance training with a placebo. Results varied across studies and dosing strategies, and the benefit depended on actually completing a resistance-training program (Forbes et al., 2021).

A newer systematic review reached a similar general conclusion: adding creatine to resistance training produced modest improvements in lower-body strength and lean tissue in older adults, although effects were not equally strong for every outcome (Liu et al., 2025).

The practical message is not that every adult over 40 needs creatine.

It is that creatine may provide additional support for selected adults who are already participating in appropriate resistance training.

What creatine does not do

Creatine does not:

• Replace strength training
• Treat the cause of joint pain
• Restore balance by itself
• Prevent every age-related change in muscle
• Guarantee faster recovery
• Replace adequate food and protein intake

What to know before taking creatine

Creatine monohydrate is the most extensively studied form.

Some people experience:

• Water-related weight gain
• Stomach discomfort
• Nausea
• Diarrhea
• Muscle cramping

People with kidney disease, impaired kidney function, significant medical conditions, or complex medication regimens should speak with a physician or pharmacist before using it.

Do not start creatine solely because an online article provides a standard dose. Product quality, health status, diet, medications, and training goals should be considered.

Calcium: Essential, but more is not always better

Calcium is necessary for:

• Bone structure
• Muscle contraction
• Nerve transmission
• Blood clotting
• Normal cellular function

Most of the calcium in the body is stored in bones and teeth.

Bone is living tissue that is continually being broken down and rebuilt. Adequate calcium intake helps provide the material needed for normal bone maintenance.

Exercise supplies a separate stimulus.

Weight-bearing activity and resistance training tell the body that the skeleton must continue supporting physical demands.

That is why bone health is not simply a calcium problem.

It may also involve:

• Resistance and weight-bearing exercise
• Hormonal changes
• Vitamin D status
• Protein intake
• Smoking and alcohol use
• Medications
• Menopause
• Medical conditions
• Fall exposure

Does calcium prevent fractures?

The answer is not a simple yes.

Some studies have found small improvements in bone-mineral density with calcium, vitamin D, or both. However, changes in bone density do not always translate into meaningful reductions in fractures.

A 2026 systematic review concluded that calcium, vitamin D, or combined supplementation produced little to no benefit for preventing fractures or falls across most studied outcomes (Bolland et al., 2026).

Other reviews have reported possible benefit in selected populations, particularly institutionalized adults or people with low intake, deficiency, or osteoporosis. Results vary by population, baseline risk, adherence, and whether calcium and vitamin D are used together.

Routine supplements should therefore not be promoted as guaranteed fracture prevention.

Food usually comes first

Calcium-rich foods include:

• Milk and yogurt
• Calcium-fortified soy milk or other fortified drinks
• Sardines or salmon with edible bones
• Tofu made with calcium sulfate
• Some fortified juices and cereals
• Kale, broccoli, and other selected vegetables

A dietitian or medical professional can help estimate whether your normal diet meets your needs.

Do not assume that a large-dose calcium supplement is safer or more effective than food.

Calcium supplements can interact with:

• Thyroid medication
• Certain antibiotics
• Some HIV medications
• Lithium
• Other prescription treatments

Supplemental calcium may also be inappropriate for some people with kidney stones, high blood calcium, kidney disease, or other medical conditions.

Vitamin D: Important for deficiency, not a universal fall-prevention pill

Vitamin D helps the body absorb calcium and supports normal bone mineralization.

It also participates in neuromuscular and other biological processes.

Low vitamin D levels can contribute to osteomalacia, bone weakness, and muscle symptoms in cases of true deficiency.

But the benefits of correcting a deficiency should not be confused with the effects of giving vitamin D to every healthy adult.

Does vitamin D improve balance or prevent falls?

Recent evidence does not support promising that routine vitamin D supplementation prevents falls.

A 2025 meta-analysis of 10 randomized trials involving more than 23,000 community-dwelling adults age 65 and older found no significant reduction in falls with vitamin D supplementation (Vilaça et al., 2025).

A separate 2023 meta-analysis also found no significant reduction in falls or fractures across the included older-adult trials (Octary et al., 2023).

A 2024 network meta-analysis reported mixed findings across vitamin D, calcium, and combined strategies. Differences in dose, baseline status, setting, and study design make the evidence difficult to reduce to one universal recommendation (Tan et al., 2024).

The safest patient-facing message is:

Vitamin D is important, but supplementation should be based on individual need rather than treated as a guaranteed balance or fall-prevention treatment.

Sunshine does not guarantee adequate vitamin D

Living in Honolulu does not automatically mean every person has adequate vitamin D.

Vitamin D status may be influenced by:

• Time spent indoors
• Sun-protective clothing
• Sunscreen use
• Skin pigmentation
• Age
• Body composition
• Diet
• Kidney or liver conditions
• Digestive disorders
• Medications

However, routine vitamin D blood testing is not recommended for every healthy adult.

Testing may be considered when a clinician identifies relevant symptoms, risk factors, bone disease, malabsorption, or another medical reason.

Avoid high-dose self-treatment

More vitamin D is not always better.

Very high vitamin D intake can lead to excessive blood calcium and serious complications.

Do not use high-dose daily, weekly, or intermittent vitamin D without medical guidance.

Magnesium: Necessary mineral, limited supplement evidence

Magnesium participates in:

• Muscle contraction and relaxation
• Nerve signaling
• Energy production
• Protein synthesis
• Blood-glucose regulation
• Normal heart rhythm
• Bone metabolism

A person who is truly magnesium deficient may experience symptoms such as weakness, fatigue, cramps, numbness, abnormal heart rhythms, or other medical problems.

However, these symptoms are not specific to magnesium deficiency.

Muscle cramps, fatigue, and weakness can have many causes.

A supplement should not be used as a substitute for medical evaluation.

Does magnesium improve physical performance?

Evidence remains limited.

An older randomized trial found that magnesium supplementation improved selected physical-performance measures in older women participating in a weekly exercise program. Benefits appeared more relevant among participants with lower magnesium intake at baseline (Veronese et al., 2014).

That trial was relatively small, involved a specific population, and does not establish that magnesium improves strength or mobility in all adults.

The practical message is:

Magnesium supplementation may matter most when intake is inadequate or deficiency risk is present. It should not be marketed as a universal muscle, cramp, or recovery solution.

Food sources of magnesium

Magnesium-rich foods include:

• Pumpkin seeds
• Chia seeds
• Almonds and cashews
• Black beans
• Edamame
• Spinach
• Whole grains
• Peanut butter
• Avocado
• Some fortified cereals

Magnesium supplement precautions

Supplemental magnesium can cause:

• Diarrhea
• Nausea
• Abdominal cramping

Very high intake can cause dangerous toxicity.

The risk is greater for people with impaired kidney function because the kidneys may not remove excess magnesium effectively.

Magnesium also interacts with:

• Some antibiotics
• Bisphosphonate osteoporosis medications
• Diuretics
• Proton-pump inhibitors
• Other medicines

Discuss timing and safety with a physician or pharmacist.

Which supplement has the strongest rehabilitation connection?

The active plan still matters most

Supplements work within the larger context of your health.

They do not independently restore:

• Leg strength
• Balance reactions
• Walking confidence
• Joint mobility
• Stair tolerance
• Lifting capacity
• Exercise habits

These abilities usually require practice and progressive loading.

A physical therapy plan may include:

• Strengthening
• Balance exercises
• Walking progression
• Mobility work
• Functional activities
• Education
• Home exercises
• Return-to-sport or return-to-activity planning

Nutrition may support that work.

It cannot perform the work for you.

Supplements and physical therapy have different roles

A physical therapist may ask about your supplements because they can affect health, symptoms, recovery, medication interactions, or safety.

Physical therapists do not replace:

• Your physician
• A registered dietitian
• Your pharmacist
• Medical testing
• Osteoporosis treatment
• Kidney or heart-disease management

Supplement decisions may need coordination with those professionals.

Questions to ask before starting a supplement

Ask your physician, dietitian, or pharmacist:

• Do I have a documented deficiency or inadequate intake?
• Can I meet this need through food?
• Does this supplement interact with my medications?
• Is it appropriate with my kidney, liver, heart, or digestive health?
• Could it affect laboratory test results?
• What dose is appropriate for my individual situation?
• How long should I take it?
• How will we know whether it is helping?
• What side effects should I watch for?
• Should I stop it before surgery?

Be cautious with supplement quality

Dietary supplements are not reviewed like prescription medications before they reach the market.

Product contents, purity, and labeling accuracy can vary.

When a clinician recommends a supplement, ask about:

• The specific ingredient
• The amount per serving
• Independent quality testing
• Unnecessary added ingredients
• Potential allergens
• Medication interactions

Avoid products that promise:

• Guaranteed pain relief
• Reversal of aging
• Instant muscle growth
• Permanent joint repair
• Complete fall prevention
• Rapid “detoxification”

When to get medical guidance first

Speak with a physician or pharmacist before starting supplements when you:

• Have kidney disease or reduced kidney function
• Have heart disease or abnormal heart rhythms
• Have osteoporosis or a history of fractures
• Have a history of kidney stones
• Have high or low blood calcium
• Have liver or digestive disease
• Take thyroid medication
• Take antibiotics, diuretics, bisphosphonates, lithium, or other prescription medications
• Are preparing for surgery
• Are receiving cancer treatment
• Are pregnant or breastfeeding

When symptoms need prompt medical attention

Seek appropriate medical care for:

• New or rapidly worsening muscle weakness
• Severe confusion, fainting, or unusual drowsiness
• Chest pain or severe shortness of breath
• An irregular or unusually slow heartbeat
• Persistent vomiting or severe diarrhea
• Severe abdominal pain
• Marked swelling
• Inability to walk or bear weight
• Symptoms beginning soon after a new supplement or dose change

This is not a complete diagnostic checklist.

The bottom line

Creatine, calcium, vitamin D, and magnesium each have legitimate roles in human health.

That does not mean every adult over 40 needs all four supplements.

Creatine may modestly support strength and lean-tissue gains when combined with resistance training.

Calcium and vitamin D are important for bone health, but routine supplementation does not guarantee fewer fractures or falls.

Magnesium is necessary for normal muscle and nerve function, but supplement benefits are most plausible when intake or status is inadequate.

Start with:

• Movement
• Strength training
• Balance work
• Walking
• Nutritious food
• Sleep
• Medical management
• A realistic rehabilitation plan

Use supplements only when they have a clear purpose and have been reviewed for safety.